Revised Abstract: "COX-2 and DNA Methyltransferase Expression and Risk Factors for Bladder Cancer", is directed by Dr. Ronald K. Ross who seeks to identify key factors in human bladder carcinogenesis drawing on the results obtained in previous well-conducted epidemiologic trials. Dr. Ross will evaluate expression of two genes involved in two different pathways, namely COX-2 and DNMTs. Strengths of the project include the availability of a large existing epidemiologic database of confirmed bladder cancer patients with laboratory data on N-acetyltransferase (NAT) and glutathione-S-transferase (GST) genotypes, and access to tumor specimens for immunohistochemistry on the majority of these cases. The project investigators have extensive expertise in epidemiology and molecular and cellular biology. The strengths in combining molecular data with epidemiology are considerable, and there is a high likelihood of success in contributing significant knowledge to the field of bladder carcinogenesis. In the previous review numerous deficiencies were identified which reduced the overall scientific merit of this project. The deficiencies included lack of integration of the statistical analyses with Core B activities, lack of innovative statistical approaches to integrate biomarker results, lack of quality control in immunochemical staining, omission of two-sided power calculations for main effects and interactions, and extrapolation of results to development of a more comprehensive index of bladder cancer progression and risk. The applicants have revised their experimental approach and outline a plan for improved integration with Core B for the statistical analyses of data to be collected for this project. It was emphasized that Drs. Mimi Yu and Susan Groshen have a longstanding collegial relationship and will be meeting regularly for discussions regarding implementation of the research, quality control, and the analytic plan. Methods for exploring the co-expression of COX-2 and DNMTs are elaborated with stratification for smoking status, vitamin C intake, and other variables. A detailed description has been provided on validation of DNMT measurements and quality control issues regarding molecular analyses of the bladder cancer specimens. Dr. Debra Hawes has been added to the project to oversee quality control issues for immunohistochemical analysis in conjunction with Core C activities, which significantly improves the quality control of the project. Power calculations have been revised to include two-tailed tests of significance, and samples sizes appear sufficient to detect approximate 10 percent differences with sufficient statistical power. Sample size considerations are given in greater detail for not only the univariate comparisons, but also for examination of two-way and three-way interactions. There is also a plan to incorporate multivariate modeling of the data for tumor stage at detection to evaluation impact of the biomarkers on progression of bladder carcinogenesis. This project has been considerably improved since the last submission and received an average merit rating of 1.4.